Materials Research Laboratory

Omicron Variable Temperature UHV STM

Location
0013 Materials Research Laboratory

Background
In Scanning Tunneling Microscopy (STM) an electrically biased tip is scanned across a surface at a very close distance (about an atomic diameter). The current flow between the tip and the sample (due to the tunneling effect) strongly depends on the tip-surface gap and can be measured with great accuracy. The changing current signal can in turn be used to generate a surface topography map. This method only works with conducting samples, e.g. metal, graphite, semiconductors.

Instrumentation
The Omicron UHV STM is equipped with Auger, LEED, Ion Gun, Electron Gun,

Several Dose Valves, Si Sublimation Source, Magnetron, High Temperature Effusion Cell. The two chambers operate at exp-12 and exp-11mBarr.

VT STM combines heating and cooling with high resolution, easy sample and tip changing.

Applications.
With the temperature range from 60K t0 1400K in STM mode the VT STM covers virtually all possible applications involving dynamic processes on surfaces, molecule adsorption and diffusion, chemical reactions, transitions, etc.